There is something to be said for a double action only handgun, revolver or semi.

When under the stress and adrenaline rush of a home defense/self defense situation a long take-up reduces the chances of an accidental discharge.

IN ALL CASES, good gun handling dictates that you keep your trigger finger alongside the frame and out of the trigger guard until the decision has been made to shoot.

A single action only pistol has you holding a gun that will go "bang" with only a sixteenth of an inch or so of finger movement to set it off.

A SA/DA requires a bit more deliberation, as the first shot requires that longer take-up, but only on the first shot. But after the first shot, the Rubicon is crossed anyway.

DAOnly is heavily favored for those who do not practice trigger control and gun handling a lot. Paradoxically, it is the action type that does require the most practice for accuracy. (Fortunately, I enjoy the practice.)

DA/SA Revolver can be used DAOnly with no change in technique from a DAOnly revolver, but can be used single action if you want.